I can't state anything about the A'pexi WSII the OP has installed on his car - no experience with system or vehicle and no pictures. I do however have experience with another "Bolt On" type of catback exhaust. The pictures posted on this thread are of a 2.5" stainless OBX designed for the '91 civic hatchback.
Fitment was dead on. I did the install myself. The issue is, based upon 18 months experience with this setup, cheap aftermarket hangers. There's no issues with mount points or load balance - it fits perfectly just like the OEM did.
What I can also state is the 2.5" is heavier than stock OEM. However, the mount degradation is not consistent with overweight stress - it wreaks of cheap materials. The pictures speak for themselves - same degredation even when "Doubled Up" and the piping is about 30-40% heavier than stock not 200% increase in weight.
I fully expect better results from the Polyurethane mounts on order. They are advertised as 80% stronger hangers and I hope they are as the weight of the larger exhaust system seems to dictate the need for increased supporting structure. At this point, I don't expect to see other damage - the OEM mounts on the car appear to be fully up to the job of supporting the 2.5" OBX catback exhaust system. I've seen threads suggesting putting adjustable hose clamps around them. I thought of doing that with my hatchback installation but doubled up on some of them instead. I will wrap with hose clamps if the polyurethane hangers fail.
I hope the polyurethane hangers are the last chapter of this book.